1. Field
The present disclosure generally presents a translucent surface (such as a milled acrylic plate) that reproduces a given target image by refracting light passing through it, as well as to techniques for designing such a surface. More specifically, the present disclosure teaches techniques for determining a lens surface pattern that refracts light in order to generate a desired image, when the lens is placed over a specific source image.
2. Description of the Related Art
Steganography refers to techniques for hiding information “in plain sight.” More formally, steganography generally refers to techniques for encoding information in covert channels in order to conceal the information and prevent detection of the encoded information. For example, a variety of techniques are available for embedding (and subsequently recovering) an encoded message in a digital image, without substantially altering the appearance of that image. Over time, steganographic techniques have ranged dramatically in sophistication and application domain, ranging from using invisible inks such as lemon juice to keep messages hidden until the right catalyst is applied, embedding images as exotic material properties using computational techniques, protecting copyrighted material using watermarks, to sophisticated visual document security for the printing of banknotes.
Some techniques are available for manufacturing three dimensional (3D) objects which reveal desired images when exposed to specific lighting conditions. For example, 3D objects may be constructed which cast shadows that form distinct images. Similarly, techniques have been developed for creating a refractive surface to deform incident light into a desired caustic pattern. Techniques such as these can be used to manipulate light and show to reproduce or create an image.